Amid the challenges posed by its 2010 merger with Houston-based Continental Airlines, United Airlines enjoyed a jubilant moment Sunday when it flew its first paying passengers aboard a new aircraft widely considered an industry game-changer.

Chicago-based United, which has struggled this year with technological glitches, poor on-time performance, consumer complaints and lagging revenue, is the first North American airline to receive the super-efficient Boeing 787 Dreamliner - the first commercial passenger jet with a fuselage, tail and wings made of mostly carbon fiber composite. At 7:28 a.m. Sunday, Flight 1116 to Chicago lifted off from Bush Intercontinental Airport.

United will maintain its growing Dreamliner fleet at its facilities at Bush Intercontinental, its largest hub, where about 60 pre-merger Continental pilots have also trained to fly the new aircraft on a flight simulator.

United and Continental airlines each ordered 25 of the mid-size, wide-body jetliners before merging. Because of production delays, United didn't receive its first 787-800 until September of this year.

"This is a very exciting day for United Airlines, a day we've waited a long time for, and we are delighted to have the 787 here," Jeff Smisek, president and CEO of the new United, said during a celebration that commenced at the crack of dawn at Gate 5 in Terminal E.

Use 20% less fuelx

Smisek described the Dreamliner as one of many planned investments to make United a better airline.

"If you want to be the world's leading airline, you need to have the world's leading airplane and we have that today in the new Boeing 787 Dreamliner," Smisek said.

With its lighter design and modern engines, the Dreamliner reportedly burns 20 percent less fuel than the similarly sized Boeing 767. Combined with the aircraft's lower seating capacity - there are 219 in three classes - the fuel efficiency makes it an ideal aircraft for international routes that don't generate enough demand to justify a jumbo jet that guzzles more fuel.

The Dreamliner's composite design also allows for passenger-pleasing features that industry insiders say may become a new standard. These include a much lower cabin altitude during flight, which is supposed to relieve headaches, dry eyes and other symptoms associated with time spent at high altitude. Windows are larger and ceilings are nearly 15 inches taller than those of the 767.

Aviation enthusiasts from across the country flew to Houston to catch Sunday's inaugural flight.

The Dreamliner is "definitely setting a new standard," said Thomas Lee, who works for a company that designed the Dreamliner's waste, water and electrical systems.

'A different airplane'

New Yorkers George Schaefer, a software developer, and Scot Titelbaum, a TV director, were planning to take the first leg of the flight and spend the day in Chicago before flying back to New York. After flying to Chicago, the plane returned to Houston before heading on to Los Angeles.

"It's a new design, it's new materials, it's just kind of a different airplane," said Titelbaum when asked why he wanted to fly it.

The second of five Dreamliners United expects to receive by year's end arrived last week and will start flying in the coming days as a spare, according to United, which announced it would fly its first batch domestically for a period of weeks before placing them on international routes in the spring.

A nonstop from Houston to Lagos, Nigeria, that United launched last year is scheduled to get Dreamliner service on Jan. 7.